FIG. 9.

Influence of the presence of purified PEA-LOS and bovine serum albumin on LptA-mediated meningococcal adherence to human cultured cells. (A) Adhesion of N. meningitidis to HBMEC in the presence of 100 μg of PEA-LOS (purified from wild-type N. meningitidis strain HT1125) during infection at MOIs of 5,000 and 50. Gray and open bars indicate the bacterial number with or without PEA-LOS, respectively. Solid bars indicate the number of bacteria adhering to HBMEC pretreated with 100 μg of PEA-LOS for 2 h prior to the bacterial infection. (B and C) Adhesion of N. meningitidis to HBMEC (B) and to A549 cells grown in serum-free medium (C) in serum-free AM during the infection assay. Opened and filled bars indicate the numbers of wild-type (HT1125) and ΔlptA (HT1222) N. meningitidis bacteria, respectively, represented as CFU. Mean CFU of adherent bacteria per 10⁴ cells in at least three experiments are shown, and error bars represent the standard errors of the means. *, P < 0.001 compared to the ΔlptA strain.